In the manufacture of proplene homopolymers and copolymers, conventional polymerization techniques using unsupported catayst result in the simultaneous production of substantial quantities of atactic polymer in addition to the desired product of high crystallinity and isotacticity. Various methods have been employed for the purfication and separation of these two polymers. The byproduct, i.e. the atactic polymer of low crystallinity is being utilized commercially as a component in various adhesive compositions, roofing materials, caulking compounds, etc.
Recently, developments have been made of new catalysts which are highly active and more stereospecific than the afore-mentioned conventional catalysts. The proportions of atactic polymer in the polymers produced employing these catalysts are substantially reduced and therefore the polymer product generall does not require any purification for removal of the atactic or low crystalline polymer. Because of the rapid adaptation of existing polymer facilities to the use of these new catalysts, there has been generated a serious shortage of low-crystalline, atactic polymers.
It is therefore an object of the present invention to provide a novel process for the production of substantially amorphous polymers of propylene and ethylene.
It is another object of the present invention to provide a process for the production of a novel amorphous polymer of propylene and ethylene and optionally a third alpha-olefin comonomer having improved physical properties.